1. Field of the Invention
The present invention relates to a power supply system including a plurality of power supply apparatuses whose inputs and outputs are respectively connected in parallel with one another.
2. Description of the Related Art
A power supply system in which a plurality of power supply apparatuses are connected in parallel is used to realize a high-output and a redundant operation. When a plurality of power supply apparatuses are used, in order to suppress an interference phenomenon (switching beat) due to the operations of the plurality of switching operations, the switching operations of the power apparatuses need to be synchronized with one another. Japanese Unexamined Patent Application Publication No. 9-163728, for example, discloses a configuration in which a slave side receives a synchronization signal from a master side to synchronize the operation timings and frequencies of the switching operations of switching power supply circuits. Japanese Unexamined Patent Application Publication No. 2011-259530 discloses a configuration in which power supply apparatuses are driven such that switching frequencies are synchronized with one another and so as to have different phase angles among them, by transmitting synchronization signals having shifted phases from a control apparatus functioning as a master to slaves.
In the power supply systems disclosed in Japanese Unexamined Patent Application Publication No. 9-163728 and Japanese Unexamined Patent Application Publication No. 2011-259530, a master power supply apparatus and slave power supply apparatuses need to be provided. Since a synchronization signal for synchronizing the timings of switching operations and frequencies has a high frequency, wiring of a transmission line for the synchronization signal makes the transmission line a source of noise generation and a portion of noise reception. Hence appropriate measures for this problem are required.